Magnetic gas sensor and methods using antiferromagnetic hematite nanoparticles
First Claim
1. A magnetic reducing gas sensor comprising:
- a source of flowing reducing gas;
a collection of antiferromagnetic nanoparticles configured as a film on a substrate;
a heater adapted to heat the substrate;
means for contacting the nanoparticles with the flowing gas; and
means for detecting changes in the magnetic properties of the nanoparticles due to the effect of the flowing reducing gas.
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Abstract
A nanoscale antiferromagnetic gas sensing apparatus and methods of measuring gas using the apparatus are described. The use of the magnetic properties of an antiferromagnetic material as gas sensing parameters explores the concept of magnetic gas sensing. According to a preferred embodiment, a nanoscale magnetic hydrogen sensor apparatus is developed based on varying of the saturation magnetization and remanence of nanoscale antiferromagnetic hematite with hydrogen flow. For example, the saturation magnetization and remanence of nanoscale hematite has been shown to increase one to two orders of magnitude in the presence of flowing hydrogen gas at concentrations in the 1-10% range and at 575 K, indicating that a magnetic hydrogen sensor using hematite material may be practical and useful for detecting hydrogen in various environments such as those wherein production, storage, transportation, and/or vehicle use of hydrogen is being conducted.
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Citations
12 Claims
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1. A magnetic reducing gas sensor comprising:
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a source of flowing reducing gas; a collection of antiferromagnetic nanoparticles configured as a film on a substrate; a heater adapted to heat the substrate; means for contacting the nanoparticles with the flowing gas; and means for detecting changes in the magnetic properties of the nanoparticles due to the effect of the flowing reducing gas. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method for detecting the presence of a reducing gas, comprising:
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providing a collection of antiferromagnetic nanoparticles configured as a film on a substrate; heating the substrate to an elevated temperature; contacting the nanoparticles with a flowing reducing gas; and detecting a change in the magnetic properties of the nanoparticles as a result of their contact with the reducing gas. - View Dependent Claims (8, 9, 10, 11, 12)
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Specification